Bispectral EEG Separates Grasping Stages
A study published in Computers in biology and medicine applies cross-frequency bispectral analysis to nonlinear EEG activity during the planning and execution of natural reach-to-grasp movements. The researchers extracted magnitude- and phase-based features from complex bicoherence matrices and assessed them through classification, permutation-based feature selection, and within-subject statistics. Execution showed stronger nonlinear coupling than planning, led mainly by beta- and gamma-driven interactions. Decoding precision versus power grasps performed similarly across the two stages, suggesting that grasp-type representations emerge during planning and persist into execution. Compared with conventional analytical baselines, bispectral features provided consistent advantages for grasp-type discrimination and multiclass classification. The findings offer a new set of motor-decoding features for future brain-computer interface and neuroprosthetic research.